LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> RX 400h AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 120 (Lighting System) >> Automatic Light Control Sensor >> On-Vehicle Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

On-Vehicle Inspection

WARNING: This page is about a different car, the 2007 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK AUTOMATIC LIGHT CONTROL SENSOR 
    1. Disconnect the A31 sensor connector.
    2. Measure the voltage and continuity of the wire harness side connector.

      HINT:

      • Ignition switch ON
      • Light control switch AUTO
      • Vehicle's surroundings are bright
        Fig 1: Checking Automatic Light Control Sensor
        G04438535Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard voltage 

      A31 SENSOR CONNECTOR (STANDARD VOLTAGE - DISCONNECTED)

      Tester Connection Condition Specified Condition
      A31-3 - Body ground Ignition switch ON 5.2 to 9.0 V
      Close driver's door again while ignition switch OFF Below 1 V

      OK 

      A31 SENSOR CONNECTOR (OK - DISCONNECTED)

      Tester Connection Specified
      A31-6 - Body ground Continuity

      If the result is not as specified, repair or replace the wire harness or connector.

    3. Reconnect the A31 sensor connector.
    4. Measure the voltage of the connector.

      HINT:

      • Ignition switch ON
      • Light control switch AUTO
      • Vehicle's surroundings are bright

      Standard voltage 

      A31 SENSOR CONNECTOR (STANDARD VOLTAGE - RECONNECTED)

      Tester Connection Condition Specified Condition
      A31-3 - Body ground Ignition switch ON 10 to 14 V
      A31-4 - Body ground Always Pulse generation

      If the result is not as specified, repair or replace the wire harness or connector.